of chemnitz



Patented Mar. 28, I 1933 UNITED STATES PATENT OFFICE JOHN 1am WILLIAMGREVE, OF CHEMNITZ, GERMANY, ABSIGNbIR TO ASTRAWERKE AKTIENGESELLSCHAFT,OF CHEMNITZ, GERIANY cancumrmo momma Application filed July 15, 1981,Serial No. 550,956, and in Austria May 88, 1981.

It is known to construct counting mechanisms with addition andsubtraction actions as reversing gears, the counting wheels cooperatingin pairs, and being adapted to be brought into operative relationshipwith driving means selectively, in such a way that the driven wheel isrotated in one direction and the other wheel in the opposite direction.The counting wheels are equi ped with shifting cams for the carrying otens, and these shifting cams act upon shifting noses on a tens carryingpawl. In the case of these counting mechanisms a separate shifting nosehas hitherto been provided for each counting wheel, but this has theadvantage that the shifting is efiected more easily by one nose than bythe other. The adjusting of such a counting mechanism is also rathercomplicated.

The invention consists in arranging a reversing gear, in which the tensshifting of both counting wheels is eflected only from a single shiftingnose of the tens carrying lever. In consequence of this arrangement, thetens carrying requires the same expenditure of power for both kinds ofcalculation, and furthermore, owing to the arrangement of the countingwheels as a whole, the driving members are shorter.

A counting mechanism according to the in vention is illustrated in theaccompanying drawing, in which Fi ure 1 shows a counting mechanism witha rac drive, and

Figure 2 a counting mechanism with a sector drive.

On the type bars 1 of the machine, which are moved up and down in aknown manner durin one stroke of the machine, racks 2 are displaceablyfitted in longitudinal slots 3 and 4, and are normally held in theosition shown in Figure 1 by a spring 5. C unting wheels 6 and 7 aremounted upon their pivots 8 and 9 in a counting mechanism frame 10,which is rotatable about a shaft 11. A downwardly projecting arm 12 ofthe counting mechanism frame is provided with a slot 13, in which thereengages a pin 14 which is riveted into a crank arm 15. The crank arm 15is pinned to a rotatable shaft 16, which is romounted upon a stationaryshaft 21, and the lower end 22 of each is constructed as a pawl with twosteps, which cooperates with a ratchet lever 23, which is constantlyulled downwards by a spring 23. It will immediately obvious from thedrawing that this ratchet lever is set free as soon as the nose 19 ofthe tens carrying lever is pressed back, and that the driving rod 2 canthen follow the pull of its spring 5, as a result of which the toothedwheel that is for the time being in mesh is rotated one division forwarIn this manner the carrying of tens for example takes place in all thedecimal places, if the counting mechanism contains a continuous series 0nines and a number is added thereto in the units column. Otherwise themethod of working of the parts described is as follows When the type bar1 is moved upwards, its

lower end being rocked in such a manner that the racks 2 are out ofengagement with the toothed wheels, the spring 5 pulls the rack 2 intoits lower position. During the d0wnstroke of the type bar, the rack 2 isbrought into engagement with the toothed wheel, and this wheel isrotated a number of teeth that corresponds to the numeral inserted. Now

March 28, 1933. J. E. w. GREVE CALCULATING MACHINE Filed July 15 1931 iJul/@1260)".- H 5 14 gram addition and one for subtraction, oo-operatingwith one another upon several axes as a reversin gear, driving means forthe counting whee s, means to bring either of the count- 5 ing wheelsinto engagement with the driving means at will, a carrying cam on eachof the counting wheels, and a single carrying nose upon the tens carring lever adapted to be directly operated y the carrying cam onwhichever of the counting wheels is for the time being engaged by thedriving means. V 2. Counting mechanism for calculating and registeringmachines, comprising a movable frame, a pair of counting wheels mountedupon several axes in said movable frame and co-operating with oneanother as a reversing gear, one wheel of each pair being for addltionand the other for subtraction, driving means for the counting wheels,means for shifting the movable frame in such a way as to bring either ofthe counting wheels mounted therein into engagement with the drivingmeans at will, a carrying cam on each of the counting wheels, and asingle carryin nose on the tens carrying lever adapted to directlyoperated by the carrying cam on whichever of the counting wheels is forthe time being engaged by the driving means.

In testimony whereof I have signed my name to this specification.

JOHN EMIL WILLIAM GREVE.

